The present invention relates to a .beta.-lactam compound wherein a specific acyl group, etc., are substituted for a hydrogen atom of the amino group of the 2-aminoacetamido group of a cephalosporin or an analog thereof (containing carbacephem nucleus) having a 7-[2-(2-aminothiazol-4-yl)-2-amino]acetamido group, a related compound thereof, and a pharmaceutical composition containing said .beta.-lactam compound.
Many .beta.-lactam antibotics have been developed in order to provide good chemical medicaments for curing various microbial infections. Among these compounds, .beta.-lactam compounds wherein a hydrogen atom of the amino group of the 2-aminoacetamido group of a cephalosporin or an analog thereof having a 7-[2-(2-aminothiazol-4-yl)-2-amino]acetamido group is substituted by various groups have been known [J. Antibiotics 35, 1022 (1980), U.S. Pat. No. 4,311,842, etc.].
It has been found that the .beta.-lactam compounds of the present invention have strong antimicrobial activities against a wide range of Gram positive and negative bacteria, particularly Gram negative bacteria including Pseudomonas aeruginosa, Pseudomonas sepatia and various Enterobacters.